MINIMIZING DEVELOPMENT OVERHEAD WITH PARTIAL PARALLELIZATION

To demonstrate the evolutionary path for porting serial applications t o the T3D as advocated by Cray Research, Inc., the authors implemented a heterogeneous, distributed, adaptive finite-element code on Cray's Y-MP/T3D system. They implemented a serial adaptive finite-element cod e on the Y-MP and, rather than fully distributing the program on the T 3D, modified only the computationally intensive portion for a massivel y parallel processing environment. A set of two communicating programs resulted-a Y-MP program that addresses mesh maintenance and modificat ion, and a T3D program that distributes the data and computations for a given mesh. The speedups achieved over a serial code demonstrate tha t significant performance gains can result from focusing the paralleli zation of serial code on smaller components, rather than attempting to derive a completely parallel implementation. Thus, a satisfactory tra de-off between implementation effort and optimal performance resulted. Although implemented in a Y-MP/T3D environment, the approach is gener ic and would work in numerous heterogeneous computing environments.